SRI International is an independent, nonprofit research institute chartered by the State of California to conduct scientific research for the public benefit. Research is conducted under contracts and grants from government agencies as well as from private sources. Renovations and improvements of the air handling systems in our main animal facility, Building T, are required to meet the needs of current and anticipated animal-related research projects, prevailing standards for care and treatment of laboratory animals, and requirements of regulatory agencies and accreditation organizations. We propose to replace our current two air handling units and exhaust fans located in the two middle wings of Building T. The current air handling units are more than 25 years old and have exceeded their life expectancy according to SRI's Facilities Department and American Society of Heating, Refrigerating and Air Conditioning Engineers (ASHRAE) recommendations. The overall objective of the proposed grant is to provide facilities that will enhance the well-being of our laboratory animal models and ensure an appropriate and predictable environment for them, ensure the quality of our biomedical research that includes laboratory animals, adequately protect researchers, and enable future expansion of our research.